The Pixel 2 XL has been under scrutiny lately for its display, but it's not alone in hardware complaints. No product is perfect, and it looks like the HTC-made Pixel 2 has at least one notable issue of its own.
Many Pixel 2 owners have been complaining about clicking and high-pitched sounds coming from the phone. One thread on the Pixel User Community has over 100 confirmations of the issue. Most of the reports about clicking are from Pixel 2 owners, but Artem has noticed the same issue on his Pixel 2 XL (#artemsluck), so it's not entirely exclusive to the smaller phone. However, the whining noise is likely normal sounds produced by the processor and other chips inside the phone.
At least for now, Google is asking people encountering the problem to start the RMA process. Turning off NFC seems to fix the clicking. Google Support told one person that a fix for both is being released "this upcoming week," but it's always best to take answers from support staff with a grain of salt. Let us know in the comments if you've noticed this problem on your Pixel 2 (or 2 XL).
Orrin, a Community Manager at Google, has responded to reports about clicking noises with this statement:
We are validating a software update to address faint clicking sounds on some Pixel 2 devices. The update will be made available in the coming weeks. The clicking noise being reported does not affect the performance of your device but if you find it bothersome you can temporarily turn off NFC in Settings > Connected devices > NFC.
It seems likely that the fix will be delivered as part of a security patch update, possibly as soon as the October update.
The November security patch includes a fix for this issue, as confirmed by Orrin, the Pixel User Community Manager. It looks like Google may be turning off NFC during phone calls, which was causing the clicking sound. Makes sense, as you're very unlikely to be using NFC while on a phone call.